Bevacizumab Beyond Progression in Metastatic NSCLC

Background: Progression on first line chemotherapy with Bevacizumab may be due to resistance developed to the chemotherapy agents used and/or bevacizumab. The objective of our single institution retrospective study was to evaluate clinical benefit, and incidence of adverse effects among patients with stage IV NSCLC receiving Bevacizumab beyond progression. Patients and Methods: Using a data base maintained in the medical oncology department of Dubai Hospital we retrospectively identified patients with stage IV NSCLC who had received Bevacizumab as part of the first line treatment protocol. Patients included in the study were those who received Bevacizumab beyond progression. Clinical benefit was defined as complete response, partial response as well as stable disease. Median duration of response and the occurrence of adverse events were documented. Median survival of the whole cohort (from the date of diagnosis to the date of last follow up or death) and following second line treatment (from the date of starting second line treatment to the date of last follow up or death) were computed. Results: Eleven patients, diagnosed between January 2008 and January 2011, who met eligibility criteria, were identified. Median age of the cohort was 55 years. Performance status range was between 0 to 2. Median number of cycles of Bevacizumab received both in the first and second line was 24. Median number of cycles of Bevacizumab received in the second line setting was six. Median duration of response was six months. Six patients (54.5 %) completed > six treatment cycles, and 3 patients (27.3 %) completed > 12 treatment cycles. One patient achieved a partial response (9.1 %), 3 patients achieved stable disease, (27.3 %), 7 patients had radiological evidence of progression (63.6 %) The clinical benefit achieved (CR+PR+SD) was 36.4 %. Grade 3/4 proteinuria occurred in 2 patients (18.2 %). Other adverse events including grade 3/4 hypertension, thromboembolic events, hematological toxicity were not observed. Median survival for the whole cohort was 23 months. Median survival after starting second line treatment was 6 months. Conclusion: In our study continuing Bevacizumab beyond progression resulted in a median duration of response and median survival similar to that reported in the literature when chemotherapy is given alone. It was not accompanied by an increase in grade 3 or 4 toxicity. Although our cohort is small the benefit of continuing Bevacizumab beyond progression is questionable. Further studies are required to confirm its clinical benefit.